Natural hot springs or special natural pools in Sri Lanka?

There are a few natural hot springs, most notably at Kanniya near Trincomalee (multiple springs with different temperatures, quite basic facilities). In the hill country there are some beautiful natural pools and waterfalls where locals swim (ask locally for safe spots). Many of the best 'secret' swimming holes are on private land or require a short hike with a guide. Be cautious with water quality and currents at waterfalls.